The ENC28J60 from Microchip is a great stand-alone ethernet controller. ENC28J60 is a 10BASE-T controller in a small form factor SOIC package with 28 pins. Featuring bandwidth of 10Mbps and onboard MAC & PHY, this controller is great for a range of applications. Microchips ethernet controllers also contain internal DMA for faster memory copying and a max speed of 25Mhz.

PHY stand for 'Physical layer'. A physical layer is the first layer in an OSI stack. PHY layer will define physical and electrical characteristics of the network.

MAC is the abbreviation for 'Medium Access Control' and is the second layer in the OSI stack. The MAC is responsible for sending and receiving RF frames.

Ethernet Communications - Microchip